In the course of the process of mineral enrichment according to known methods, the mineral grains are displaced in enrichment plants under the influence of a pulsating motion of water and the thrust of the supplied mass of raw material, along trajectories lying in vertical planes running directly from the place of delivery of the material fed mechanically for dressing to the place of receiving the products being enriched. The length of the path necessary to perform the separation of the mixture of the mineral grains, and thus the length of the entire device employed for the enrichment constitutes a characteristic value to estimate the effectiveness of the method of enrichment and of the design of the enrichment devices.
There are known methods of enrichment of minerals under restricted sedimentation of grains in a pulsating and flowing aqueous medium, according to which the raw mixture of minerals before the enrichment process is submitted to a desludging process, in a separate operation, consisting in removing the finest grains from the raw material. The desludging process is realized according to known methods beyond the enrichment device. Said principles concern also, and form a basis of designing jigs having a cylindrical or approximately to cylindrical form.
From the Russian Pat. No. 195,997, a cylindrical jig is known in which the raw material is supplied, the heavy fraction being taken off from a ring-shaped working trough adjacent to the central axis, the light fraction on the other hand being drained off at the entire periphery of the water box.
From the French Pat. No. 1,269,592, a cylindrical jig is known, in which the raw material is supplied near the central axis of the jig, the heavy and the light fractions being taken off through receivers located near the external wall of the jig.
In a known cylindrical jig, according to the German Pat. No. 47,967, the raw material is supplied in at the central axis on a conical surface over which it flows in a radial direction into a working trough near the external wall thereof. The raw material is separated within said trough after according to the specific gravity of the grain and is displaced radially from the external wall towards the central axis. The light fraction flows out through a trap offtake arranged below the sieve deck, the heavy fraction being taken off through the holes of the sieve deck.
In the known cylindrical jigs mentioned hereinabove, in course of the separation process of mineral grains, independently of the manner of supplying the raw material and of taking off of the separation products, the grains are displaced along vertical radial planes.